• 제목/요약/키워드: surface activation

검색결과 1,422건 처리시간 0.025초

현장 굴착 실험을 통한 사면붕괴 거동 연구 (A Study on behavior of Slope Failure Using Field Excavation Experiment)

  • 박성용;정희돈;김영주;김용성
    • 한국농공학회논문집
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    • 제59권5호
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    • pp.101-108
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    • 2017
  • Recently, the occurrence of landslides has been increasing over the years due to the extreme weather event. Developments of landslides monitoring technology that reduce damage caused by landslide are urgently needed. Therefore, in this study, a strain ratio sensor was developed to predict the ground behavior during the slope failure, and the change in surface ground displacement was observed as slope failed on the field model experiment. As a result, in the slope failure, the ground displacement process increases the risk of collapse as the inverse displacement approaches zero. It is closely related to the prediction of precursor. In all cases, increase in displacement and reverse speed of inverse displacement with time was observed during the slope failure, and it is very important event for monitoring collapse phenomenon of risky slopes. In the future, it can be used as disaster prevention technology to contribute in reduction of landslide damage and activation of measurement industry.

Modulation of Subcellular Ca2+ Signal by Fluid Pressure in Rat Atrial Myocytes

  • Woo Sun-Hee;Morad Martin
    • Biomolecules & Therapeutics
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    • 제14권1호
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    • pp.19-24
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    • 2006
  • Atrial chambers serve as mechanosensory systems during the haemodynamic or mechanical disturbances, which initiates arrhythmia. Atrial myocytes, lacking t-tubules, have two functionally separate sarcoplasmic reticulums (SRs): those at the periphery close to the surface membrane, and those at the cell interior (center) not associated with the membrane. To explore possible role of fluid pressure (FP) in the regulation of atrial local $Ca^{2+}$ signaling we investigated the effect of FP on subcellular $Ca^{2+}$ signals in isolated rat atrial myocytes using confocal microscopy. FP was applied to whole area of single myocyte with pressurized automatic micro-jet (200-400 $mmH_2O$) positioned close to the cell. Application of FP enhanced spontaneous occurrences of peripheral and central $Ca^{2+}$ sparks with larger effects on the peripheral release sites. Unitary properties of single sparks were not altered by FP. Exposure to higher FP often triggered longitudinal $Ca^{2+}$ wave. These results suggest that fluid pressure may directly alter excitability of atrial myocytes by activating $Ca^{2+}$-dependent ionic conductance in the peripheral membrane and by enhancing spontaneous activation of central myofilaments.

Potential drug targets in the GPCR-$G{\alpha}_{12}/G{\alpha}_{13}$ signaling pathways

  • Kim, Sang-Geon
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 2008년도 Proceedings of the Convention
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    • pp.89-99
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    • 2008
  • GPCRs are large families of cell surface receptors that transmit signals through conformational changes upon ligand activation and an interaction with the heterotrimeric G-proteins. GPCRs regulate the cell-signaling pathways and participate in the regulation of physiological processes through the G-proteins defined by their ${\alpha}$ subunits. A family of 20 G protein-coupled receptors (GPCRs) that provide a large class of tractable drug targets for new anti-inflammatory drugs and, in certain instances, for the treatment of the inflammatory indications such as atherosclerosis, rhinitis, asthma, pulmonary disease and arthritis. In view of the important findings showing that $G{\alpha}_{12}/G{\alpha}_{13}$ regulate the various cellular processes such as actin-stress fiber formation, neurite retraction, platelet aggregation, gene induction, and apoptosis, we became interested in whether, after coupling to the activated GPCRs, the G-proteins and their downstream molecules might be involved in the pathologic processes of chronic inflammatory diseases (e.g., liver fibrosis). In this symposium, the possible link of the G-proteins with the pathophysiology will be discussed with the aim of finding potential new drug targets.

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Quality Comparison of Activated Carbon Produced From Oil Palm Fronds by Chemical Activation Using Sodium Carbonate versus Sodium Chloride

  • MAULINA, Seri;HANDIKA, Gewa;Irvan, Irvan;ISWANTO, Apri Heri
    • Journal of the Korean Wood Science and Technology
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    • 제48권4호
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    • pp.503-512
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    • 2020
  • Using Na2CO3 versus NaCl as chemical activator, we compared the quality of activated carbon produced from oil palm fronds as raw material. These activators were selected for comparison because both are readily available and are environmentally friendly. In the manufacturing, we used Indonesian National Standard (SNI 06-3730-1995) parameters. For the quality comparison, we determined activated-carbon yield, moisture, ash, volatiles, and fixed-carbon contents; and adsorption capacity of iodine. The best characteristics, assessed by morphological surface analysis and Fourier transform infrared (FTIR) spectral analysis, were observed in the carbon activated by Na2CO3 at an activator concentration of 10% and carbonization temperature of 400 ℃. The results were as follows: activated-carbon yield, 84%; water content, 8.80%; ash content, 2.20%; volatiles content, 14.80%; fixed-carbon content, 68.60%; and adsorption capacity of iodine, 888.51 mg/g. Identification using the FTIR spectrophotometer showed the presence of the functional groups O-H, C=O, C=C, C-C, and C-H in the Na2CO3-activated carbon.

겉보리 및 쌀보리의 수화속도 (Absorption of Water by Husked and Naked Barley)

  • 이종숙;김성곤
    • 한국식품과학회지
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    • 제15권3호
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    • pp.220-224
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    • 1983
  • 겉보리(올보리와 강보리) 및 쌀보리(세도하다가와 백동)를 각각 40 및 30%도정한 다음, 20, 30 및 $40^{\circ}C$에서 6시간 침지하면서 수화속도를 검토하였다. 수화속도는 수화시간의 평방근에 비례하였고, 확산계수 ($D,\;cm^{2}/min$)는 D = $D_{0}\;{\exp}\;(-E_{a}/RT)$로 표시되었다. 확산계수 값은 강보리가 돌보리보다 다소 높았으며, 세도하다가와 백동은 비슷하였다. 쌀보리의 확산계수는 겉보리보다 다소 높았다.

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무릎 반월판 절제술 후 신경근 조절 운동이 안쪽빗넓은근의 근활성에 미치는 영향 : 단일사례연구 (The Effect of Neuro-Muscular Control Training on Vastus Medialis Oblique Activity After Menisectomy of Knee : Case Study)

  • 김기철;서현규
    • 대한정형도수물리치료학회지
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    • 제20권1호
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    • pp.39-45
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    • 2014
  • Background: The purpose of this study is to identify effects of neuro-muscular control training on vastus medialis oblique (VMO) after menisectomy of the knee. Methods: The subjects of this study are women aged 42 and 39 each who did menisectomy. Case 1 was applied quadriceps setting exercise and neuro-muscular contrlol training and case 2 was applied quadriecps setting. Intervention was done 5 times a week for 2 weeks. Measurement of muscle activity on VMO and vastus lateralis (VL) was standardized signals of each muscle to %RVC using surface EMG. Results: On comparison of exercise before and after on VMO and VL, VL activation of case 2 was increased more than case 1. Conclusion: Quadriecps-setting exercise and selective neuro-muscular control training of VMO is effective intervention on VMO activity and muscle activity ratio of VMO to VL.

Thermal Decomposition of Tetrakis(ethylmethylamido) Titanium for Chemical Vapor Deposition of Titanium Nitride

  • Kim, Seong-Jae;Kim, Bo-Hye;Woo, Hee-Gweon;Kim, Su-Kyung;Kim, Do-Heyoung
    • Bulletin of the Korean Chemical Society
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    • 제27권2호
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    • pp.219-223
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    • 2006
  • The thermal decomposition of tetrakis(ethylmethylamido) titanium (TEMAT) has been investigated in Ar and $H_2$ gas atmospheres at gas temperatures of 100-400 ${^{\circ}C}$ by using Fourier Transform infrared spectroscopy (FTIR) as a fundamental study for the chemical vapor deposition (CVD) of titanium nitride (TiN) thin film. The activation energy for the decomposition of TEMAT was estimated to be 10.92 kcal/mol and the reaction order was determined to be the first order. The decomposition behavior of TEMAT was affected by ambient gases. TEMAT was decomposed into the intermediate forms of imine (C=N) compounds in Ar and $H_2$ atmosphere, but additional nitrile (RC$\equiv$N) compound was observed only in $H_2$ atmosphere. The decomposition rate of TEMAT under $H_2$ atmosphere was slower than that in Ar atmosphere, which resulted in the extension of the regime of the surface reaction control in the CVD TiN process.

Crystal structure of the pretense domain of an ATP-independent heat shock protease HtrA

  • Kim, Dong-Young;Kim, Dong-Ryoung;Ha, Sung-Chul;Neratur K.Lokanath;Hwang, Hye-Yeon;Kim, Kyeong-Kyu
    • 한국결정학회:학술대회논문집
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    • 한국결정학회 2002년도 정기총회 및 추계학술연구발표회
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    • pp.24-24
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    • 2002
  • HtrA (high temperature requirement A), a periplasmic heat shock protein, is known to have molecular chaperone function at low temperatures and proteolytic activity at elevated temperatures. To investigate the mechanism of functional switch to pretense, we have determined the crystal structure of the N-terminal protease domain (PD) of HtrA from Thermotoga maritima. HtrA PD shares the same fold with chymotrypsin-like serine professes. However, crystal structure suggests that HtrA PD is not an active pretense at current state since its active site is not formed properly and blocked by an additional helical lid. On the surface of the lid, HtrA PD has hydrophobic patches that could be potential substrate binding sites for molecular chaperone activity. Present structure suggests that the activation of the proteolytic function of HtrA PD at elevated temperatures might occur by the conformational change.

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Association of BAF53 with Mitotic Chromosomes

  • Lee, Kiwon;Shim, Jae Hwan;Kang, Mi Jin;Kim, Ji Hye;Ahn, Jong-Seong;Yoo, Soon Ji;Kim Kwon, Yunhee;Kwon, Hyockman
    • Molecules and Cells
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    • 제24권2호
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    • pp.288-293
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    • 2007
  • The conversion of mitotic chromosome into interphase chromatin consists of at least two separate processes, the decondensation of the mitotic chromosome and the formation of the higher-order structure of interphase chromatin. Previously, we showed that depletion of BAF53 led to the expansion of chromosome territories and decompaction of the chromatin, suggesting that BAF53 plays an essential role in the formation of higher-order chromatin structure. We report here that BAF53 is associated with mitotic chromosomes during mitosis. Immunostaining with two different anti-BAF53 antibodies gave strong signals around the DNA of mitotic preparations of NIH3T3 cells and mouse embryo fibroblasts (MEFs). The immunofluorescent signals were located on the surface of mitotic chromosomes prepared by metaphase spread. BAF53 was also found in the mitotic chromosome fraction of sucrose gradients. Association of BAF53 with mitotic chromosomes would allow its rapid activation on the chromatin upon exit from mitosis.

Acute Phase Protein Lipocalin-2 Is Associated with Formalin-induced Nociception and Pathological Pain

  • Jha, Mithilesh Kumar;Jeon, Sangmin;Jin, Myungwon;Lee, Won-Ha;Suk, Kyoungho
    • IMMUNE NETWORK
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    • 제13권6호
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    • pp.289-294
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    • 2013
  • Lipocalin-2 (LCN2) is an acute-phase protein induced by injury, infection, or other inflammatory stimuli. LCN2 binds small hydrophobic ligands and interacts with cell surface receptor to regulate diverse cellular processes. The role of LCN2 as a chemokine inducer in the central nervous system (CNS) has been previously reported. Based on the previous participation of LCN2 in neuroinflammation, we investigated the role of LCN2 in formalin-induced nociception and pathological pain. Formalin-induced nociceptive behaviors (licking/biting) and spinal microglial activation were significantly reduced in the second or late phase of the formalin test in Lcn2 knockout mice. Likewise, antibody-mediated neutralization of spinal LCN2 attenuated the mechanical hypersensitivity induced by peripheral nerve injury in mice. Taken together, our results suggest that LCN2 can be therapeutically targeted, presumably for both prevention and reversal of acute inflammatory pain as well as pathological pain.